"Andreas Raab" <andreas.raab at gmx.de> wrote:

> I'd actually recommend an abstract class (like Mailer or WebBrowser) which
> defines:
> 
> * the top-level protocols a client can rely on
> * a registry for all of the possible implementations
> * a well known default implementation

What I've got now is an AppRegistry class that holds all the registering
behaviour, and has a #preferred method to give you whichever one you
told it you'd prefer to use. (Probably #default is a better name,
though.) WebBrowser is a subclass of it with no extra behaviour
whatsoever, and MailSender can be a subclass of it too (as soon as I get
around to it). MailSender also defines some extra stuff that's common to
all mail senders (it holds some information like SMTP server and user
name). I like the idea of also using them to document the top-level
protocols.


Adam Spitz